Electrical connector



Dec. 30, 1969 T. M. CAIRNS ELECTRICAL CONNECTOR Filed Dec. 22, 1967THOMAS M C A/RNS INVENTOR mg 1%" ATTORNEYS United States Patent US. Cl.339176 3 Claims ABSTRACT OF THE DISCLOSURE An electrical connector isformed by inserting a terminal of electrically conductive material intoa terminal block of electrically nonconductive material. The terminal iscylindrical in form and has an annular recess about the circumferencethereof. The terminal block has both an aperture therein for receivingthe terminal and an opening therein which intersects a portion of theaperture. The cylindrical terminal is inserted in the aperture of theblock until a portion of the annular recess thereof is aligned with theopening intersecting the aperture. A locking member is inserted in theopening and a portion thereof projects into the intersected part of theterminal receiving aperture to enter the annular recess of the terminaland thereby secure the terminal to the block.

BACKGROUND OF THE INVENTION Electrical connectors are formed byinserting a terminal or plurality of terminals of electricallyconductive material into a terminal block of nonconductive material.

Many different types of connectors are available for utilization inconstructing electrical circuit packages in which interconnection ofvarious electrical components is necessary. Most of todays electricalconnectors require that for assembly of the terminal and the terminalblock, the terminal must be aligned in an exact position with respect toa terminal receiving aperture of the block. If the terminal is notaccurately aligned with the aperture, the terminal, the block or eitherof them may be damaged or broken when the terminal is inserted. Thepre-alignment of the terminal and its receiving aperture in the blockis, of course, an expensive operation in that either sophisticatedmechanical handling apparatus or human operators are necessary to alignthe terminal and aperture prior to terminal insertion.

Another problem encountered with the electrical connectors constructedin accordance with present day teachings is that the terminals, onceinserted in a terminal block, tend to become dislodged. Thereafter, theconnectors do not function properly when they are assembled with otherconnectors. The dislodgement of such terminals also causes malfunctionsand shorting of the electrical equipment interconnected by theterminals.

The electrical connector of this invention is so designed that theinsertion of the terminals into the terminal block can be accomplishedwithout prior orientation of the terminals and the block. The connectorof this invention has the terminals thereof secured to the terminalblock in such a manner that they do not become dislodged after assembly.The electrical connector of this invention is, therefore, moreeconomical to fabricate and more reliable in operation.

SUMMARY OF THE INVENTION This invention is directed to an electricalconnector and, more particularly, the invention is directed to theconstruction of an electrical connector in which a terminal ofelectrically conductive material may be easily inserted into a terminalblock of nonconductive material and subsequently secured thereto.

The connector of this invention is formed by inserting a terminal ofelectrically conductive material into a terminal receiving apertureformed in a terminal block of electrically nonconductive material. Theterminal is formed so as to have at least a first cylindrical surfacearea of a first diameter and another cylindrical surface area concentricwith the first surface area and of smaller diameter than the firstdiameter. The surface area of smaller diameter forms a depressed portionof the terminal having the shape of an annular recess about thecircumference of the terminal.

The terminal block is formed so as to have both an aperture therein forreceiving the cylindrical terminal and an opening therein, in part,intersecting the terminal receiving aperture along a portion of thelength of the aperture. A locking member is receivable in the opening ofthe terminal block and the locking member has a portion thereof whichprojects within the terminal receiving aperture of the block at the areaof intersection of the aperture and opening.

When a terminal is positioned within the terminal receiving aperturewith a portion of the annular recess thereof aligned with the portion ofthe opening intersecting the aperture, the locking member may insertedin the opening. The portion of the locking member which pro? jectswithin the terminal receiving aperture enters the aligned annular recessof the terminal and locks the terminal to the block.

Since the depressed portion of the cylindrical terminal forms an annularrecess about the entire circumference of the terminal, the terminal maybe received in the terminal receiving aperture of the terminal block anda portion of the annular recess will always be aligned with the openingintersecting the aperture. The locking of the terminal to the block bythe locking member which projects Within the annular recess insures thatthe terminal will not become dislodged with respect to the block duringsubsequent utilization or handling of the connector.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is an elevational view whichshows an electrical connector constructed in accordance with theteachings of this invention. FIGURE 2 is a plan view taken along line 22of FIGURE 1 which shows both the electrical connector of 'FIGURE 1 and,in shadow, a cooperating electrical connector also formed in accordancewith the teachings of this invention. FIGURE 3 is an elevational View,in cross section, taken along line 33 of FIGURE 2 which shows the mannerin which the terminals are secured to the terminal block by the lockingmember. FIGURE 4 is an isometric view which shows electrical terminalsformed in accordance with the teachings of this invention. FIGURE 5 is aview similar to FIGURE 3 but which shows another embodiment of anelectrical connector formed in accordance with the teachings of thisinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Construction In FIGURE 1 thereis shown an electrical connector constructed in accordance with theteachings of this invention and generally identified by the numeral 10.As best seen in FIGURE 2, the connector 10 has a plurality of terminals,generally identified by the numeral 12, the terminals being formed ofelectrically conductive material such as beryllium copper. Each of theterminals 12 is received in a terminal receiving aperture 14 formed in aterminal block 16. The terminal block 16 is constructed from anonconductive material, such as a plastic, and may be formed in amolding operation.

The electrical terminals 12 are best shown in FIGURE 4 wherein both amale terminal and a female terminal are shown. The terminals are formedso as to have a first cylindrical surface area 18 of a first diameterand a second cylindrical surface area 20 of a diameter approximating thediameter of the first cylindrical surface area. Intermediate andinteconnecting the first cylindrical surface area 18 and the secondcylindrical surface area 20 is a portion of the terminal which definesan annular recess 22 about the circumference of the terminal 12. Thedepressed metal 23, forming the bottom of the annular recess 22, has acircular cross section of a diameter smaller than the diameter of thefirst cylindrical surface area 18.

The annular recess 22 of the terminal 12 may be formed by machining outthe recess in an otherwise solid, cylindrical terminal. On the otherhand, the recess 22 may be formed by rolling the recess into a thin walltubular member so as to form the female terminal and by rolling in therecess 22 and a nose 24 to form the male terminal. The terminals 12 areconnected by connector strips 26 to beaded strands of electricalconductors 28, best seen in FIGURE 2. The annular recess 22 may beformed in the terminals 12 by many other ways known to those skilled inthe terminal forming art.

The terminal block 16, shown in elevational view in FIGURE 1, has aplurality of already described terminal receiving apertures 14 therein.The terminal receiving apertures, in the connector of the preferredembodiment, are of circular cross section with a diameter slightlylarger than the diameter of the first and the second cylindrical surfaceareas 18 and 20' of the electrical terminal 12. As seen best in FIGURE1, the plurality of terminal receiving apertures 14 are in a verticallystacked arrangement having two rows with equal spacing bet-ween thecenters of each of the apertures in each of the two rows.

In the central portion of the terminal block 16, as viewed in the planview of FIGURE 2, an opening 30 is provided along the full verticaldimension of the block. The opening 30 also has a guideway 32. As bestseen in FIGURE 3, the opening 30- of the terminal block 16 intersects,in part, a portion of each of the terminal receiving apertures 14. Moreparticularly, as viewed in FIGURE 3, the opening 30 intersects the rightside of the apertures 14 in the left row and the left side of theapertures in the right row.

A locking member, generally designated by the numeral 34, is received inthe opening 30. A guide 36 formed on the locking member 34 is receivedin the guideway 32 of the opening 30 so as to guide the locking memberas it moves along the length of the opening after insertion therein. Thelocking member 34 has formed integrally therewith projecting portions38, best seen in FIGURE 2, which extend into the various terminalreceiving apertures 14 of the terminal block 16.

In its preferred embodiment, each of the plurality of terminal receivingapertures 14 formed in the terminal block 16 has an annular ridge 40projecting into each of the apertures at the front thereof (FIGURE 1).The purpose of these ridges is to locate each of the terminals 12 withinits particular terminal receiving aperture 14.

Assembly and operation The electrical connector 10, in accordance withthe teachings of this invention, is assembled in the following manner.With reference to FIGURE 2, a terminal 12 is inserted in each of theterminal receiving apertures 14 of the terminal block 16. Since each ofthe terminals 12 are cylindrical and since each of the annular recesses22 thereof or also cylindrical, each of the terminals 12 may be insertedin the terminal block without any prepositioning of the terminal at aprescribed angular attitude with respect to the block. It should beunderstood that the terminal receiving aperture 14 may be of anyearnfiguration which permits the free insertion of the cylindrical terminals12 without prepositioning of the terminals.

Each of the terminals 12 is inserted into its associated aperture 14until the front of the terminal engages the annular ridge 40 of thereceiving aperture. At this particular position, the terminal is at itsfully inserted position and a portion of the annular recess 22 thereofis aligned with a portion of the opening 30 which intersects thespecific terminal receiving aperture 14. Since the terminal has anannular recess about its entire circumference, the terminal may be inany position within the terminal receiving aperture and still have aportion of its recess aligned with the opening 30.

After the terminal has been properly positioned, other terminals may beinserted in selected apertures of the terminal block so as to completethe assembly of the connector. Once the desired number of terminals 12or inserted in the block 16, the locking member 34- is placed in theopening 30 of the terminal block 16 with a guide 36 thereof entering theguideway 32 so as to locate the locking member in its travel along theopening 30. As the locking member is inserted and moved along theopening 30, the projecting portions 38 on each side of the lookingmember associated with the two rows of terminals, enter the associatedterminal receiving apertures and the annular recesses 22 of theterminals located in the block. When the locking member is moved to itsfully inserted position, the projecting portions 38 thereof secure allof the inserted terminals 12 to the block because the various portionsof the projecting portions are received in respective ones of theannular recesses 22 between two areas 18 and 20 of greater diameter.Thus, the terminal is locked in the block from lateral movement althoughthe terminal may be freely rotated if that is desired. Such a mountingof the terminal substantially reduces the possibility of dislodging theterminal during use or handling of the connector.

While the specific description above was addressed to an electricalconnector wherein a plurality of female terminals were arranged in avertically stacked array, it

should also be obvious that a plurality of male terminals,

such as shown in FIGURE 2, may also likewise be locked in a maleterminal block 42. The terminal block 42 is made so that the terminalreceiving apertures 44 thereof are of a size sufficient to confine themale terminals 12 received therein.

Alternate form In FIGURE 5 an alternate form of an electrical connectorformed in accordance with the teachings of this invention is shown. Inthis particular form of the electrical connector 110, a pair of lockingmembers 134 and 136 are utilized to lock a plurality of terminals 112 inthree vertical rows. The locking member 134 is received in an openingand the locking member 136 is received in an opening 132. The lockingmember 134 is sufiiciently large such as described for the first form ofthe connector to lock two vertical rows of terminals 112 in positionwithin the terminal block 116. However, the locking member 136 issmaller than the member 134 and is designed to lock only one row ofelectrical terminals 112 in position.

There has been described herein an electrical connector in which aterminal of electrically conductive material is inserted within anonconductive terminal block and secured thereto without the necessityof orienting the terminal with respect to the terminal block beforeinsertion. Once inserted, the terminal is secured to the block easilyand quickly and the terminal is precisely located with respect to theblock.

Many modifications of the electrical connector of this invention will beapparent to one skilled in the art in view of the teachings of thisspecification. It is intended that all modifications which fall withinthe true spirit and scope of this invention be included within the termsof the appended claims.

What is claimed is:

1. An electrical connector which comprises:

a plurality of cylindrical, electrical terminals, each of said terminalsbeing formed both so as to be of generally fixed diameter and so as tohave an annular recess therein about the circumference of said terminal,said annular recess being located intermediate areas of said terminal offixed diameter;

a terminal block of electrically nonconductive material formed so as tohave a plurality of circular, terminal receiving apertures aligned intwo rows with a uniform distance between said rows, each of saidapertures for receiving an individual one of said plurality ofcylindrical terminals;

an opening in said terminal block along the length of adjacent sides ofsaid two rows of terminal receiving apertures, said opening in part,intersecting a portion of each of said plurality of terminal receivingapertures at a location which is adjacent said annular recess of saidterminal when said terminal is inserted in each of said apertures; and

a locking member movable along said opening of said terminal block, saidlocking member having project ing portions thereon for locking saidterminals to said block, said projecting portions being located onopposite sides of said locking member associated with said rows of saidterminal receiving apertures.

2. An electrical connector as defined in claim 1 wherein a plurality ofterminal receiving apertures are aligned in a plurality of rows; whereina plurality of openings are provided in said terminal block rather thansaid single opening; wherein said plurality of openings intersecting, atleast in part, portions of different ones of said plurality of terminalreceiving apertures at locations which are adjacent said annularrecesses of said terminals when said terminals are inserted in each ofsaid apertures; and wherein a plurality of locking members are provided,each of said locking members being formed so as to be receivable in anassociated one of said openings, each of said locking members also beingformed with projecting portions thereonwhich enter the-terminalreceiving apertures associated with an individual one of said openingsto secure said terminals inserted in said apertures to said block.

3. The electrical connector as defined in claim 1 fur ther comprising:

means for locating said plurality of electrical terminals withinindividual ones of said plurality of terminal receiving apertures insuch relative positions that said annular recess of each of saidterminals is aligned with that portion of said opening from which saidprojecting portion of said locking member will extend into said terminalreceiving aperture to lock said terminal to said block.

Ill

References Cited UNITED STATES PATENTS 25 2,964,725 12/1960 Lehr et al.

FOREIGN PATENTS 2/ 1941 Great Britain. 7/1963 Great Britain.

KENNETH DOWNEY, Primary Examiner

